body{background: whitesmoke;}
.body{width: 1200px;height: auto;margin: 0 auto;overflow: hidden;margin-top:30px;}
.left-nav{width: 200px;height: auto;float:left;border:  1px solid gainsboro;background:#FFF}
.content{width: 955PX;height: auto;margin-left:20px;float:left;padding:10px;background:#FFF}